1. Field of the Invention
The present invention relates to medical instruments, particularly to a vibratory device for treating female voiding dysfunctions associated with functional and organic changes in the urethra and bladder neck.
2. Description of Prior Art
Most often met form of voiding dysfunctions is urinary incontinence. According to data from the January 1991 issue of "Lovett Underwood Neuhause & Webb", over 10 million Americans, i.e. 4 percent of the U.S. adult population alone suffer from some form of urinary incontinence. The economic impact of urinary incontinence is enormous and is likely to rise as the number of elderly in the population increases. In accordance with data from the Journal of Urology, April 1988, urinary incontinence in the elderly is a major social problem. The annual cost of incontinence care in the U.S. alone currently exceeds $10 billion.
One of the most frequent type of urinary incontinence is the so-called stress urinary incontinence, which is defined as the involuntary loss of urine through the intact urethra as the result of a sudden increase in intra-abdominal pressure in the absence of bladder activity. Stress urinary incontinence accounts for roughly 75% of all female urinary incontinence. The most common cause of stress urinary incontinence in female is malfunction of the sphincteric mechanism of the bladder and an inadequate reaction of pelvic floor muscles.
Urinary incontinence is difficult to treat. Treatment of urinary incontinence falls in to three main categories: (1) surgery; (2) drug therapy; (3) reeducation, including bladder retraining programs and reeducation of the pelvic floor muscles. The existing urinary incontinence treatment methods and instruments, however, are far from being completely successful, and despite long-term and repeated course of treatment, recurrences are not uncommon.
Treatment of patients by means of mechanical vibration induced by specially designed vibratory instruments is established therapeutic method and has been known since nearly century. Short-term localized vibration has been noted to intensify blood circulation, increases assimilation of oxygen by tissue, and alters the activity of some enzymes. Therefore the vibration affects directivity of metabolic processes.
Low-frequency (10-200 Hz) vibratory stimulation as a form of therapy has been successfully used in variety of disorders to improve muscle contractivity, reduce spasticity and decrease inflammation.
Different frequencies and amplitudes of vibratory stimulation may exert their influence on contraction/reflection of muscles.
Based on information about the therapeutic effect of vibratory stimulation, one can anticipate that the use of endourethral dosed vibratory stimulation (massage) should be a very effective procedure in the treatment of patients suffering from different types of voiding dysfunctions.
The authors have developed a series of vibratory mechanically expandable urethral bougies for treating female voiding dysfunctions. One such instrument is disclosed in U.S. Pat. No. 4,773,400, issued Sep. 27, 1988 to G. Borodulin, et al. According to one of the embodiments of that invention, the bougie comprises a rotary drive unit, a probe consisting of two resilient rods with the front ends of the rods being permanently pivotally connected to each other and opposite ends being fixed in the housing of the drive unit, and a rotary elliptical or oval-shaped cam between the above-mentioned rods, the cam being connected to the output element of the drive unit, so that rotation of the cam causes periodic expansions and contractions of the resilient rods. When the probe is inserted into the urethra of a patient suffering from a voiding dysfunction, the patient's urethra is subjected to massaging vibratory action which is extremely efficient for treating diseases of the urethra and the neck of the urinary bladder. In order to prevent pinching of mucosa of the urethra walls, the edges of the rods on their mating surfaces are chamfered.
Although the instrument described above is quite efficient in its action, permanent pivotal connection of the front ends of the rod does not allow disconnection of the rods. This creates inconveniences in cleaning.
Besides, the contraction of the rods depends only on resilient properties of the rods themselves, i.e., there is no positive means for returning the rods into the contracted state. After many repeated cycles of expansion and contraction, the material of the rods may change or partially lose its resiliency whereby vibratory treatment conditions and radial expansion forces applied to the urethral walls also may change. This, in turn, will change the vibratory treatment conditions.
Although chamfers on the edges of the rods protects the urethral wall mucosa from pinching, they reduce the contracting areas of the rods which increases the pressure on the unit surface of the contacting area. Furthermore, the chamfers are not always sufficient for protecting the mucosa from pinching.
If the probe is inserted into the urethra and enters the patient's bladder when the bladder is not preliminary emptied, during the treatment the urine may flow out from the bladder through the split-type probe to the outside. This will create inconveniences both for the patient and for the urologist. If, however, the bladder is not filled, it is difficult to transmit the vibratory forces to the bladder detrusor muscles, i.e., to the walls of the bladder.